mw66nova

iTrader: (13)

probably. the best way to do it is to start all over at the factory jetting and try again.

GreggymacZ28

Okay thanks alot, ill get the new pump in there and let you guys know what happens next week!

GreggymacZ28

Does anyone know how i should mount the electric fuel pump? I'm kind of lost on trying to figure out where the best spot should be. And i run a filter between the pump and the regulator? And also i heard people mount it behind the tank? Anyone know? Theres not much about them on here that shows where they are mounted.

xpndbl3

iTrader: (5)

most mount them on the bottom of the trunk well or the spare tire area under the car. Plenty of room for a sumped gas tank, a pre- filter, then pump then a post filter under there.

GreggymacZ28

Yeah that seems to be the answer i found most often as well. So i just run a filter between the tank and pump, and then the regulator somewhere up close to the carburetor is what im thinking. Thanks guys!

GreggymacZ28

Alright im officially lost on what's wrong with my car. I just boguht a holley blue pump with a regulator and ran it today at the track, and it ran a solid 7 psi all the way down and never even moved. Car felt really nice, and the plugs checked out to be perfect, just the right amount of color to them.

And my best time was 13.47...and i was averaging 13.70's. My fastest mph at the end of the track was 99 mph today. I lost 3 mph since last week without changing anything but the pump? Im lost completely on why it's not running faster. Im beginning to think its just slow. But the only other thing i can possibly think of is my exhaust being stock besides headers and y-pipe is really killing me?

mw66nova

iTrader: (13)

so it keeps getting progressively slower?

hmm.

something else is wrong. is it making any weird noise? is the valvetrain in good shape (and up to the task?)

GreggymacZ28

haha, exactly. It almost seems as though the more money i spend, the slower my car gets. But no, there is nothing wrong, it runs perfect. Theres never any wrong noise, theres nothing that ever seems wrong. It's almost as though theres just a e.t. limiter on my car or something, as it will run solid all the way through, just slow.

Im almost positive the valvetrain is good, because i havnt heard anything sounding abnormal from inside there, and it doesnt run bad. Every time the cars at the track it runs consistent. It's always within 1-2 tenths on that given day. But like you said, something has to be wrong, i just can not figure it out.

mw66nova

iTrader: (13)

ok, before you spend any more money, stop! put the car on jackstands, take all 4 wheels off, and go over that baby from bumper to bumper with a fine toothed comb and see if you can find anything weird.

i found a locked up caliper this way which was costing me 2 mph. make sure you're getting 100% WOT. make sure your timing mark on the balancer hasn't slipped. make sure nothing crazy is going on with the trans and rear causing a bind, etc.

GreggymacZ28

Yeah thats about exactly what i was going to do. Supposedly this should atleast be running mid 12's i was thinking? I'm not spending anymore money till i can figure out what is wrong. I just dont know what to look for because the only thing not working is the top end speed. My mph is basically what is suffering. Maybe it is the carb. I'll go through it again and check everything out.

pancherj

What was the difference in weather between your best and worst run? The DA at my home track regularly ranges from 1000' to over 3000'. That will cost me 3MPH and a few tenths.

But, I agree that your car should be faster. Are you sure it isn't going into valve float? Are you sure the plug reading is good? I find it nearly impossible to read the plugs on pump gas motors (including my own). It isn't like reading racing-gas-only plugs.

Checking for WOT and balancer slip are good suggestions. I've been bitten by both of those!

GreggymacZ28

The difference was a decent amount im sure. It was really humid and when i ran the fastest time it had cleared up and was sunny for a little. Also, yeah ill have to check all of that. Its just a tough task looking at a car that has no sign of anything being wrong, just slow. I hope i can find something. Thanks guys!

pancherj

You can go to dragtimes.com and check the DA for whatever track you ran at, the date and the time.

Orr89RocZ

iTrader: (20)

Assuming that once you fixed the fuel pressure prob, you put the stock carb jetting back in?

GreggymacZ28

Not back to stock, but just 2 jet sizes larger. I didnt want to run too lean again so that i'd damage my motor.

xpndbl3

iTrader: (5)

What did the fresh set of plugs you put in the motor say? Otherwise you're just shooting in the dark.

GreggymacZ28

They were just a little brown not too much color and not white.

Are there certain plugs i should be using? I used Ac Delco 41993 stock type gapped at .060 and then i have the GM performance HEI distributor and coil. Should i run any different plugs or gap?

Orr89RocZ

iTrader: (20)

I like a tighter gap but as long as its burning clean and making rpm and power, leave em where its at.

xpndbl3

iTrader: (5)

I never gap bigger than .045 and typically my higher compression motors are .035 or less if on spray. I like NGK plugs they leave a nice color on the strap to read. Perhaps toss in a fresh set, make a run and swap out a few at the return road and post pics for us to help. Or you can always keep jetting richer until it stops picking up MPH and go from there.

mw66nova

iTrader: (13)

tr55 gapped at .045" is what i'd suggest

pancherj

Maybe this is my problem with reading plugs. I use Autolite's (2934 is the number that comes to mind) and they show no color on the strap and the porceline is bone white (all the way to the bottom) for my best ET's.

GreggymacZ28

Ok, ill go pick up some new plugs then and try them with a .045 gap and see how they do.

Also, i just went out and checked the intake vacuum on my car, and at idle in park the vacuum is 12 at around 1250 rpm. And with the car in gear the vacuum is 10 at 900-1000 rpm. I read that in holleys you get the vacuum and divide by 2 and then subtract by one or two and that gives you what your power valve needs to be. Does this mean that my 6.5 power valve needs to be canged? Like a 4.5? or 3.5? And could this be another reason why im not running what i should?

Another question(sorry, i have plenty of them) when you guys say vortec's like total timing around 34*, do you mean total timing at what rpm? Because mine is total of 34* at 2500 rpm. Is that about right?

GreggymacZ28

By the way, heres a shot of the car you all have been helping me with. It seems to be taking off pretty well!

pancherj

Is that 35* at 2500RPM with the vacuum advance hooked up? If yes, that could be your problem. You want 35* at 2500-3000RPM with the vacuum advance unhooked and the vacuum port on the carb plugged.

GreggymacZ28

No the vacuum advance is not hooked up, and also am not running any vacuum to the vacuum advance on the car at all. So i had it all around 34-38 trying different runs and never had really any differences.

DIGGLER

iTrader: (1)

are those buick wheels or oldsmobile wheels?

GreggymacZ28

Buick wheels, my dad just sold his 1970 buick gs so im using the wheels for awhile.

overdriv

My experience with Vortec heads is they are about at their max around 5000RPM on my 406SBC. They might pull a 355 to 6000, but unless they have had some work done to them by someone familiar with Vortec heads they run out of air early. Might not be your problem, but you do have a fairly big cam in there that may not be the best with the vortecs.

GreggymacZ28

Thats what i was thinking but guys on the truck sites are running the same cam and bigger with stock vortec heads, and are running into the 11's by a pretty decent margin. I saw a few guys running this same combination before i put this cam in which is why i went with it.

Shagwell

Power valve isn't likely effecting your WOT power, tuning it in properly is mostly for street drive-ability.

Timing makes power, right up to the point of detonation. Typically, you want as much as you can get & getting it in as fast as possible. - Every engine is different on what the final numbers will be. Just for racing purposes, vacuum advance is not needed and won't make a difference, it is again a street drive-ability tuning aid.

GreggymacZ28

Ok i have some new good info! I recently borrowed a buddy of mines lc-1 wideband to see if i could get this thing figured out. I got it installed and then ran the car down a back road at wot and did my shift and everything as if it was the track.

First off im idling at 12.0-12.4. I was thinking that's pretty rich for idle? And then as soon as i got on the gas at wot it stays pretty consistent between 10.0-10.5. So obviously im pretty rich. I was thinking at wot i should be between 12.8-13.1? Is it running this rich what killing all the power i was hoping to have? Thanks guys!

xpndbl3

iTrader: (5)

I idle 14.7-15.0 but my cam has a lot of overlap, so read fresh plugs and decide for yourself. Next peak power is typically 12.5-13.2 range but that's if you didn't foul out plugs running in the 10s. A fouled out plug can screw with your readings. I always bring several sets of plugs to the track, make one hit and swap them with fresh ones until I'm in the general area.

GreggymacZ28

Yeah i sandblasted the old ones, but i just got my new sparkplugs in an hour ago, the ones with the .045 gap so hopefully those will help me a little more, and then i can get this thing dialed in!

And yeah 12.5-13.1 seems to be what i read everywhere. Also i knew idle needed to change it just seemed that with my cam being big i didnt know if idle should run a little richer than 14.7 or not.

GreggymacZ28

Now with new plugs and new jet sizes (73/80) Its still running rich. dropped about 4 jet sizes on both primaries and secondaries. It was at 12.0-12.3 at idle and then 11.6-12.0 at wot. So it did increase some. But on one pull it sputtered and dropped to 9.6 but that only happened once. When i got back home i adjusted the idle screws and now my idle is at 14.4-14.7 so im hoping that is alright. It seems it gets really rich after 2 seconds and then slowly leans out with mph but not by much.

Its really giving me a hard time here,aha. Any suggestions would help me at this point!

GreggymacZ28

Alright well im beginning to think that my cam might be too big for my vortec heads. I was thinking i might switch heads...But would depend on the amount of money i could get some for. Does anyone know any heads that would work well with my 110 lsa, 236/242 duration @ .050, and .520/.540 cam, and that would net me around a low 12 or high 11?

It seems hard to find a budget head, and i am shooting for anything under $1,000. If theres no way then i'll just forget about it! I've seen alot about brodix, dart, and even patriot heads, but i want to make sure i do it right if i do change. Thanks guys.

mw66nova

iTrader: (13)

why not just put a better matched camshaft in it? an xe274h would run circles around that cam, and would work well with the rest of your combo. would cost way less...

GreggymacZ28

That was going to be what i was going to do if i couldnt get any heads. My only worry about the xe274 is will it run a noticable difference? I just dont want to buy it for it not too show an obvious difference. As of right now with this cam im running 13.2's. If it would even net me 12.8's consistently then i'd be happy with that cam.

I've read alot of good things on it, i just didnt know if my heads were really holding me back or not.

mw66nova

iTrader: (13)

10:1 350 with vortec heads and an xe274 with a well matched converter and gear in a 3200-3400lb car is a well known bottom 12 second combo

GreggymacZ28

In that case xe274 it is! I hope im right that im over cammed? The car just seems that no matter what i do to it or how much money or how far and wide i change the jets it will not break a 13.20. It's what makes me think the cam and heads just arent a good match.

xpndbl3

iTrader: (5)

i ran a bigger cam and ran better than low 12s with vortec heads, how about working on the combo at the track with traction and tune it

GreggymacZ28

Really what was your cam size? And were your heads ported or anything like that? And for tuning ive gone from a 6.5 power valve down to a 5.0. And then ive jetted the primaries all the way from 68-78 and secondaries all the way from 72-84. Traction doesnt seem to be a problem, im pulling 1.70 60 foots.

Another main problem im having is that when i pull in first and the car shifts from 1-2 right after it shifts at around 5900 it starts to stumble and then the rpms sit down low and dont climb for a whole second or two, and then all of a sudden it shoots up to 6300 where i shift and all is fine. But i'm almost positive thats killing it. I thought it was too rich and i had 70 primaries and 78 secondaries. I lowered it to 68 primaries and 76 secondaries and it didnt stumble and pulled pretty hard and i got a 103 mph(my fastest with the new cam). Next run...the stumble was back with a 99 mph.

It just seems to me that with this cam i cant even get back anywhere close to the mph i had last year with the other cam. I also opened up the exhaust yesterday at the track to open headers, and it ran the exact same times. And i had the stock 2.25 inch exhaust all the way back from the y-pipe i was almost positive that was killing something.

mw66nova

iTrader: (13)

something else isn't right then...go back over the car and make sure you didn't miss something obvious

Orr89RocZ

iTrader: (20)

yeah its a big cam but not really overcammed for what you were trying to achieve. It doesnt sound like your setup is running close to optimal yet. Theres tune issues and possibly trans issues? Cam swap is not gonna cure those issues.

pancherj

I agree, a cam swap will not fix your problem. Borrow a different carb and try it. Back in post 41, you went to a different track and lost a ton in the 60', but went faster overall. Why? With the old pump that barley held enough PSI on a run, you were doing better than with the new pump that is holding steady at 7psi. Why? It almost sounds as if your HSAB's are too active or your float level is creeping up. I would borrow a carb and throw it on there to see what happens. Also, 6500RPM is not a bad shift point with that setup. Lastly, go over all of your time slips and correct them for the DA (use dragtimes.com) so you can see if you are really losing or gaining or holding steady. Also, look at your splits on every slip. Make a spreadsheet or get a log book.

GreggymacZ28

I am putting the q-jet that i had on there last season when i ran my 12.97 pass back on next time im at the track. Ive been going over the car over and over and i cant find anything. I got a new fuel filter and i checked my psi all day yesterday and it was a steady 7. Also on those runs i made where like you said go by the DA. It was one run i would get 103 mph and the next 98. With no change at all. Ive been going by mph, and thats what seems to be all over the board. Shifting the same spot every time.

I also dont think its the trans, because its not like somethings messing up or feeling wrong in the shift, just the exhaust crackles and pops as though somethings not working with the afr. This whole time since i put this new cam and carb on ive felt like my problem was in the air/fuel. I just cant find the source. Thanks again guys, i realize my build is a gloomy one, haha. It seems as though theres never a breakthrough, and that's where the frustration is at.

GreggymacZ28

So i've removed the holley and put the q-jet back on, and that got me to inspecting the holley. One thing ive read in my holley tuning book is that air bleed modification can be a major killer to the carb. So i decided to give it a look, knowing i bought this used.

I know that the high speed air bleeds are the ones in the center of the carb, with the idle ones on the outside? Well, if on the secondary side on only one side of the carb, the air bleed is 2-3 times larger than on the primary side. Is this normal? Or is this what my issue has been?

mw66nova

iTrader: (13)

Yes, the high speed air bleeds are towards the inside, no that's not normal. Sounds like someone was playing with something they shouldn't have.

GreggymacZ28

Okay well that could atleast let me know not to waste my time with that carb anymore. I'll let you guys know how the q-jet runs then, that'll tell if it was a fuel issue or not. Thanks!

GreggymacZ28

Well, i figured it out! That holley must have had something wrong with it. Took the car to the track today and the only thing we changed was the carb. Just changed it back to the q-jet.

Well, my fastest run of the day was a 12.67 @ 106.16 mph. I wish i wouldve realized it was the carb along time ago, but oh well! It felt good to finally run what i was hoping. It's also finally consistent! It was running after the timing was set, 12.67,12.68,12.70, and 12.72. So hopefully i can contend in the points now!

Thanks again for everyones help, finally my sob story of a car has been replaced.

pancherj

Post up the new full slip. And congrats! Feels good doesn't it?!